In general, a vehicle includes a battery for supplying power to various electric loads and an alternator for supplying power generated during vehicle driving to the battery and the electric loads.
Recently, research has been actively conducted into an eco-friendly car that uses a high-voltage battery as an energy source, such as a hybrid electric vehicle (HEV) and an electric vehicle (EV) due to problems in terms of energy saving and the environment.
The above battery for a vehicle is frequently charged and discharged under various conditions such as a driving condition and an electric load operating condition and, thus, there is a problem in that a service lifetime of the battery is reduced.
Referring to FIG. 1, a battery includes a metal grid 10 for a negative electrode and a positive electrode, an active material 20 (PbO2) coated on the grid 10, and so on. The grid 10 provides electric contact between a positive active material and a negative active material, allowing current to flow.
When a predetermined time period elapses after the battery is discharged, interfacial resistance between the grid 10 and the active material 20 increases and, then a heating value during charging and discharging increases, forming a grid corrosion layer including Pb-Oxide and PbnO at an interface of the grid 10, which contacts the active material.
In particular, there is a problem in that capacity of an active material is reduced due to the grid corrosion layer and a service life of a battery is reduced.
For reference, capacity of the active material is reduced due to change in materials in a battery, that is, due to sulphation, shedding, softening, etc. as follows.                Sulphation: Irreversible lead sulfate crystallization.        Shedding: Phenomenon of shedding an active material due to mechanical stress such as over-discharge.        Softening: Phenomenon of weakening bond between particles of an active material due to reduction in electrical conductivity.        
In addition, although a battery controller installed in a vehicle, that is, a battery management system (BMS) appropriately manages charging and discharging properties of a battery, there is a problem in that a battery is not sufficiently charged as a service life of a battery decreases and when a battery is left for a long time in a discharged state due to customer's mistakes, there is a problem in that an active material in a battery is immobilized, remarkably reducing a battery lifetime.